The Effect Of Melatonin On Calcium Overload Of Fetal Mouse Brain Cells Due To Lipopolysaccharide

Objective : To observe the effects of intracellular calcium in the brain cells of acutely isolated fetal mouse and investigate the protection of melatonin on brain injury, by injecting lipopolysaccharide in the abdomen of SD pregnant rats of 19 days of pregnancy.Methods: The 72 pregnant Sprague-Dawley rats of 19 days of pregnancy were divided randomly into three groups:the intrauterine infection group (LPS group), the melatonin group (MT group) and the blank control group, 24 in each group. In LPS group, the pregnant rats received an intraperitoneal (i.p.) injection of LPS (500μg/kg). the control group injected with saline intraperitoneally. In MT group, the rats were treated with LPS 500μg/kg and MT 10 mg/kg simultaneously. Then, the fetuses were removed by laparotomy, according to the time after injection, respectively: 1h,6h,12h,24h,48h,72h, and the brain tissues were isolated acutely. Novel fluorescent probe Fluo-3/AM loaded fetal rat brain cells. The average fluorescence intensity of intracellular calcium of fetal rats was detected by flow cytometry.Results:1. With the observation time of injected LPS group, the calcium fluorescence values of brain cells are significantly increased at 6h and peaked at 12h, were significantly higher (P<0.001)at different time points. And 1h and 6h compared, 6h and 12h compared, 12h and 24h compared, 24h and 48h compared, all P<0.05; 48h and 72h compared, P>0.05, but still on an upward trend.2. The value of calcium fluorescence in the MT group at 72h is lower than the LPS group at 72h, but is not statistically significant (P>0.05), The value of calcium fluorescence in the MT group at 6h and 12h is significantly lower than the LPS group (P<0.001), the calcium fluorescence of other groups at each time point were significantly lower than LPS group (P<0.05). Conclusions:1. LPS result in brain damage by inducing intracellular calcium overload in brain cells of fetal rat.2. Intracellular calcium overload is an important part of the mechanism of brain cell injury of fetal rat.3. Melatonin has a protective effect on lipopolysaccharide-induced brain cells injury of fetal rat by inhibiting intracellular calcium overload. With the deepening of the study on the pathogenesis of HIE, which will provide a new treatment strategies and methods for the protection of brain injury in HIE.